1. Field of the Invention
The present invention relates to a central processing unit (CPU) core, and more particularly, to a recoverable and fault-tolerant CPU core and a control method thereof.
2. Discussion of Related Art
A central processing unit (CPU) core means hardware which reads an instruction stored in a memory or a disk, performs a specific calculation on operands according to an operation encoded in the instruction, and executes an algorithm for a specific application by storing the calculated result again.
The CPU core is widely being applied to every field of a system semiconductor. For example, the CUP core may be applied to media data processing for massive multi-media data such as video data compression and decompression, audio data compression and decompression, and audio data conversion, and sound effects. Further, the CPU core is extensively applied to network data processing, a touch screen, a controller for home appliances, a minimum performance microcontroller platform such as a motor control, a wireless sensor network, and microelectronics.
The CPU core includes a core, a translation lookaside buffer (TLB), and a cache, A job performed by the CPU core is prescribed by a combination of a plurality of instructions. Instructions stored in the memory are sequentially input to the CPU core, and the CPU core performs a calculation corresponding to the input instructions every clock cycle.
The TLB performs a function of converting a virtual address into a physical address for driving an operating system-based application, and the cache temporarily stores the instruction stored in an external memory, and thus a speed of the CPU core may be increased.
Meanwhile, development of a driver assistance system such as an advanced driver assistance system (ADAS) is actively being performed in recent automobile electronics fields. Specifically, in order to implement an apparatus for recognizing an external environment of an automobile instead of a driver, a possibility in which a high performance CPU core using a clock having a frequency which is equal to or more than 500 MHz is used is high. Here, the recognition of the external environment of the automobile may include motion detection, pedestrian recognition, driving pattern or drowsiness recognition, driving assistance through lane detection.
In order to improve recognition performance of the external environment, reliability of the CPU core should be ensured. That is, the CPU core used in the automobile electronics field has a main function of recognizing when the CPU core does not normally operate.
For example, in an application which directly controls an automobile steering device by recognizing data outside the automobile, reliability of the CPU core is very important. This is because reliability of the CPU core has a direct influence on a life of the driver when the CPU core abnormally operates due to factors such as voltage, current, temperature, etc.